The present invention relates to absorbent articles such as diapers, incontinence briefs, pull-on diapers, training pants, diaper holders and liners, sanitary hygiene garments, and the like. More particularly, the present invention relates to absorbent articles providing ease of application and removal, sustained dynamic fit, prevention of leakage, sustained wearer comfort, and desirable appearance.
When absorbent articles such as diapers and training pants are worn, gaps tend to form between the article and the body. Because leakage can occur through these gaps, the designs of absorbent articles typically include features intended to sustain the proper fit on the body. For example, the designs of many absorbent articles include leg cuffs located generally along the side edges which form the leg openings when the articles are worn. Leg cuffs, in general, are known variously in the art as leg cuffs, leg bands, side flaps, barrier cuffs, containment flaps, and/or elastic cuffs.
Outer leg cuffs are located distally from the longitudinal centerline, relative to other leg cuff elements that may be present, and typically have elastic elements sandwiched between layers of the materials making up a main structure of the article. This main structure is typically the containment assembly or a side structure which is attached to the containment assembly and which forms ears to give the overall article an hourglass shape. In general, the outer leg cuff elastic elements provide contractive forces tending to draw the materials against the legs and thus form gaskets to prevent leakage, while also providing a range of elastic extensibility to allow the absorbent article to be fitted onto the body of a wearer.
However, the shapes of absorbent articles are often distorted by elastic features. For example, the contractive forces of the elastic waist features, elastic side panels, and/or elastic leg cuffs tend to draw the distal edges of the leg openings upward and inward, thus effectively rotating the leg openings toward a longitudinal orientation. This longitudinal orientation makes the insertion of the wearer""s feet and legs more difficult and especially aggravates the difficulty of application of pre-closed absorbent articles having inner leg cuffs, which tend to catch the wearer""s feet and toes during insertion.
In some designs of absorbent articles, the upper edges of the leg openings are formed by the lower edges of elastic side panels. Because these elastic side panels often are designed to provide forces intended to support the article on the body of the wearer, the forces they provide may be ineffective in preventing gapping around the legs. Examples of designs having leg openings formed by elastic side panels are described in U.S. Pat. No. 4,938,757 issued to Van Gompel et al. on Jul. 3, 1990. The designs of some elastic side panels include angled elastic components having one end located on or near the front edge of the waist opening and another end located on or near the back edge of the leg opening. However, an elastic component which is angled downward toward the back exerts a downward force on the front portion of the article, which may lead to gapping around the leg openings. Examples of designs having side panels including angled elastic components are described in U.S. Pat. No. 5,669,897 issued to Lavon et al. on Sep. 23, 1997 and U.S. Pat. No. 5,899,895 issued to Robles et al. on May 4, 1999.
When an elastic leg cuff is designed to generate a high contractive force in an attempt to minimize gapping, the high force often causes discomfort to the wearer and/or creates pressure marks on the body. This problem is especially difficult to avoid in designs having outer leg cuffs containing elastic strands, which tend to exert concentrated forces on the wearer. The high contractive force may also tend to make application and/or removal of the article difficult.
The designs of some outer leg cuffs have the elastic components inset some distance from the edge of the leg openings. However, the inset elastic components of outer leg cuffs are typically incapable of drawing the actual edges of the leg openings against the legs of the wearer. As a result, the effectiveness of such outer leg cuffs as gaskets to prevent leakage is limited.
Another disadvantage of some typical designs of outer leg cuffs is that the appearance of the raw edges of the sheet or web materials surrounding the leg openings differs appreciably from that of a durable garment or of a disposable absorbent article having the garment-like appearance desired by many users. In attempts to improve the appearance, some absorbent articles have material wrapped over the edges of the leg openings, that is, folded over the edges of the materials. However, these designs have another disadvantage in that the added layers of materials tend to resist the contractive forces exerted by the elastic components. Examples of wrapped cuff designs are described in U.S. Pat. No. 6,171,290 issued to Boisse et al. on Jan. 9, 2001. In some designs, strips of soft padding material are wrapped over the edges of the leg openings. These designs have the same disadvantage of additional resistance to contraction. Examples of designs with soft padding are described in U.S. Pat. No. 5,064,421 and U.S. Pat. No. 5,797,824 both issued to Tracy on Nov. 12, 1991 and Aug. 25, 1998, respectively.
Thus, it would be beneficial to provide an absorbent article designed to sustain the proper fit of the article around the legs of the wearer. It would also be beneficial to provide an absorbent article having improved appearance around the legs. It would be of further benefit to provide an absorbent article having a reduced possibility of leakage at the legs. Additionally, it would be of benefit to provide an absorbent article having easy application and/or removal and, in particular, easy insertion of the feet and legs of a wearer into the leg openings of the article. And, it would be of benefit to provide an absorbent article also providing improved comfort for the wearer.
The present invention provides absorbent articles, such as diapers, incontinence briefs, pull-on diapers, training pants, feminine hygiene garments, and the like, which may provide some or all of the benefits of ease of application and removal including, in particular, easy insertion of the legs into the leg openings, sustained dynamic fit, prevention of leakage, sustained wearer comfort, and desirable appearance. Such an absorbent article is intended to be fit about a wearer""s body to contain excreta and/or bodily exudates.
The absorbent article has a containment assembly having a front waist region, a back waist region opposed to the front waist region, a crotch region disposed between the front waist region and the back waist region, a front end edge, a back end edge, opposed side edges, a topsheet, a backsheet, and an absorbent core disposed at least partially between the topsheet and the backsheet. When the absorbent article is closed for wearing, portions of the side edges generally adjacent the front and back end edges are fastened or joined together, the remaining portions of the side edges define two leg openings, and the front end edge and the back end edge define a waist opening. The margins of the leg openings of the absorbent article have an elastic extensibility of at least about 50%.
The absorbent article may also have, at the margin of each leg opening, at least one outer leg cuff. The outer leg cuff and the adjacent materials may be mechanically incrementally stretched to provide a large amount of elastic extensibility as well as differential extensibility. The outer leg cuff may be folded or wrapped over the side edges of the materials defining the leg openings.
The absorbent article may thus provide ease of application and removal, sustained dynamic fit, prevention of leakage, sustained wearer comfort, and desirable appearance.